This disclosure relates to a gas turbine engine radial impeller. More particularly, the disclosure relates to a configuration for cooling the radial impeller using vapor cooling.
A gas turbine engine uses a compressor section that compresses air. The compressed air is provided to a combustor where the compressed air and fuel is mixed and burned. The hot combustion gases pass over a turbine to provide work that may be used for thrust or driving another system component.
Gas turbine engines continue to get smaller as pressure ratios are increased in an effort to improve fuel burn. Axial compressors typically lose their efficiency as they become smaller such that the use of radial impellers becomes more attractive for compact gas turbine engines.
Radial impellers are limited in temperature capability due to the thermal gradients between the root and tip of the impeller. A vapor cooling scheme has been proposed to reduce the temperature of the impeller. The radial impeller incorporates a vapor cooling cavity having a phase change material that changes phase between a liquid and a gas to provide cooling to the impeller tip. The proposed designs have not been practical in terms of operability or manufacturability.